1. Technical Field
The present invention relates to a piezoelectric element, a piezoelectric actuator device, a liquid ejecting head, a liquid ejecting apparatus, and an ultrasonic measuring apparatus.
2. Related Art
In the related art, a piezoelectric element is generally formed by interposing a piezoelectric layer formed of a piezoelectric material between two electrodes. This piezoelectric element is widely used as an ultrasonic transmitting element or an ultrasonic receiving element in an ultrasonic measuring apparatus, a flexural vibration mode actuator device in a liquid ejecting head, and the like. As a representative example of a piezoelectric material used for this type of the piezoelectric layer, lead zirconate titanate (PZT) is included (see JP-A-2001-223404). PZT basically has a structure of a rhombohedral crystal and shows piezoelectric characteristics (distortion quantity) by inducing electric dipole moment which occurs by applying an electric field.
As the piezoelectric material, a material used for so-called 90° domain rotation which is different from the above-described principle has been known. This piezoelectric material shows the piezoelectric characteristics (distortion quantity) for example, in such a manner that an electric field is applied to a tetragonal crystal in which an a-axial component, a b-axial component, and c-axial component are mixed, and thus the a-axial component and the b-axial component are rotated by 90° for the c-axial component.
However, recently, a liquid ejecting head having higher density and higher performance has been required. Improvement of a piezoelectric constant of a piezoelectric layer in which displacement occurs by using 90° domain rotation is also desired.